Raja Raja Chola I (Tamil: born Arunmozhi Thevar (also called as Raja Kesari Varman Raja Raja Devar and respectfully as Peruvudaiyar), popularly known as Raja Raja the Great, is one of the greatest emperors of the Tamil Chola Empire of India who ruled between 985 and 1014 CE. He established the Chola empire by conquering the kingdoms of southern India expanding the Chola Empire as far as Sri Lanka in the south, and Kalinga (Orissa) in the northeast. He fought many battles with the Chalukyas in the north and the Pandyas in the south. By conquering Vengi, Rajaraja laid the foundations for the Later Chola dynasty. He invaded Sri Lanka and started a century-long Chola occupation of the island. He streamlined the administrative system with the division of the country into various districts and by standardising revenue collection through systematic land surveys. Being an ardent devotee of Lord Shiva, he built the magnificent Peruvudaiyar Temple (also known as the Brihadeeswarar Temple) in Thanjavur and through it enabled wealth distribution amongst his subjects. His successes enabled his son Rajendra Chola I to extend the empire even further.

The key dates of Raja Raja are difficult to come by, scholar N Sethuraman, concludes that he was born in circa 947 ACE, was crowned on 18 July 985 and died in 1014 in the Tamil month of Maka.

Rajaraja Chola was born as the third child of Parantaka Sundara Chola (Parantaka Chola II (957–973 CE).